117 lines
3.7 KiB
Rust
117 lines
3.7 KiB
Rust
// Copyright 2015-2017 Parity Technologies (UK) Ltd.
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// This file is part of Parity.
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// Parity is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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// Parity is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with Parity. If not, see <http://www.gnu.org/licenses/>.
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//! Request chain builder utility.
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//! Push requests with `push`. Back-references and data required to verify responses must be
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//! supplied as well.
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use std::collections::{HashMap, VecDeque};
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use request::{
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IncompleteRequest, CompleteRequest, Request,
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Field, OutputKind, Output, NoSuchOutput, Response,
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};
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/// Build chained requests. Push them onto the series with `push`,
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/// and produce a `Requests` object with `build`. Outputs are checked for consistency.
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#[derive(Debug, Default, Clone, PartialEq, Eq)]
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pub struct RequestBuilder {
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output_kinds: HashMap<(usize, usize), OutputKind>,
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requests: Vec<Request>,
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}
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impl RequestBuilder {
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/// Attempt to push a request onto the request chain. Fails if the request
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/// references a non-existant output of a prior request.
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pub fn push(&mut self, request: Request) -> Result<(), NoSuchOutput> {
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request.check_outputs(|req, idx, kind| {
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match self.output_kinds.get(&(req, idx)) {
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Some(k) if k == &kind => Ok(()),
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_ => Err(NoSuchOutput),
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}
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})?;
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let req_idx = self.requests.len();
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request.note_outputs(|idx, kind| { self.output_kinds.insert((req_idx, idx), kind); });
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self.requests.push(request);
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Ok(())
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}
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/// Convert this into a "requests" object.
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pub fn build(self) -> Requests {
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Requests {
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output_kinds: self.output_kinds,
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outputs: HashMap::new(),
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requests: self.requests,
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offset: 0,
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}
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}
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}
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/// Requests pending responses.
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#[derive(Debug, Clone, PartialEq, Eq)]
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pub struct Requests {
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output_kinds: HashMap<(usize, usize), OutputKind>,
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outputs: HashMap<(usize, usize), Output>,
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requests: Vec<Request>,
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offset: usize, // offset for splitting.
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}
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impl Requests {
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/// For each request, produce responses for each.
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/// The responses vector produced goes up to the point where the responder
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/// first returns `None`, an invalid response, or until all requests have been responded to.
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pub fn respond_to_all<F>(mut self, responder: F) -> Vec<Response>
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where F: Fn(CompleteRequest) -> Option<Response>
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{
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let mut responses = Vec::new();
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let mut found_bad = false;
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let offset = self.offset;
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let output_kinds = self.output_kinds;
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let mut outputs = self.outputs;
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for (idx, req) in self.requests.into_iter().enumerate().map(|(idx, req)| (idx + offset, req)) {
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let complete = req.fill(|req_idx, out_idx| outputs.get(&(req_idx, out_idx)).cloned().ok_or(NoSuchOutput))
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.expect("All outputs checked as invariant of `Requests` object; qed");
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match responder(complete) {
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Some(response) => {
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response.fill_outputs(|out_idx, output| {
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match output_kinds.get(&(idx, out_idx)) {
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None => {},
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Some(out) => if out == &output.kind() {
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outputs.insert((idx, out_idx), output);
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} else {
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// output kind doesn't match expected.
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found_bad = true;
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}
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}
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});
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if found_bad {
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return responses;
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}
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responses.push(response);
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}
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None => return responses,
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}
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}
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responses
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}
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/// Get access to the underlying slice of requests.
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pub fn requests(&self) -> &[Request] { &self.requests }
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}
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